Refrigerating means with air pump



June 1950 H. w. PROTZELLER REFRIGERATING mus wrm AIR PUMP cmcun- 5 Sheets-Sheet 1.

Filed Nov. 18, 1943 June 1950 H. w. PROTZELLER mammm'rmc mus wrrn AIR PUMP cmcurr 5 Sheets-Sheet 3 Filed NOV. 18, 1943 June 20, 1950 H. w. PROTZELLER REF'RIGERATING MEANS wn'n AIR PUIIP cmcun 5 Sheets-Shoot 4 Filed NOV. 18, 1943 ja zjfiagezzer June 20, 1950 H. w. PROIZELLER REFRIGERATING IEANS WITH AIR PUIP CIRCUIT 5 Sheets-Shoot 5 Filed Nov. 18, 1943 79zue/zf0r [Jug ler Patented June 20, 1950 REFRIGERATING LIE-ANS WITH AIR PUMP CIRC UIT

Harry W. Protzeller, Fairmont, Minn., asslgnor oi one-half to Arthur Wm. Nelson, Park Ridge, Ill.

Application November 18, 1943, Serial No. 510,747

13 Claims. 1

This invention relates to improvements in refrigerated food products, and means for and methods of refrigerating and distributing food products, and it consists of the matters hereinafter described and more particularly pointed out in the appended claims.

One of the objects of the invention is to provide a refrigerated food product and methods and means for processing and distributing the same where'with there is retained in the food product, to a greater extent than heretofore, the flavor, color, essential minerals, vitamins and volume.

It is also an object of the present invention to provide improved means for refrigerating food products by methods which retain, to an extent greater than in prior commercial practice, the

4 scale of Figs. 2 and 3.

flavor, color, essential minerals, vitamins and volume of the food products.

A further object of the invention is to provide improved means for refrigerating products and which is adapted to be exteriorly carried by an aircraft into a low temperature high altitude air and wherein heat units are transmitted through the outer covering of container to atmosphere to thus accomplish the refrigerating operation.

Another object of the invention is to provide a food product container having improved features better adapting it to the reception of the product packages, and the utilization of the container during refrigerating and transporting operations.

Again, it is an object of the invention to provide an improved package for the product to be refrigerated which shall be adapted to be associated with others of similar construction to facilitate the refrigerating operation.

It is also an object of the invention to provide methods and means whereby vehicles not designed for the transportation of products requiring refrigeration may be readily used for such purposes without any substantial structural change in the vehicle itself.

The above mentioned objects of the invention, as well as others, together with the several advantages thereof will more full appear as the specification proceeds.

In the drawings:

Fig. 1 is a longitudinal vertical sectional view through a pressure temperature chamber assembly by which a part of the improved method of refrigerating products may be carried out.

Fig. 2 is a transverse vertical sectional view through a part of the assembly shown in Fig. 1, on an enlarged scale, as taken on the line 22 of said Fig. 1.

Fig. 5 is a perspective view of one form of product container that may be used in connection with the assembly of Fig. 1 in carrying out the improved method of refrigerating food products.

Fig. 6 is a longitudinal vertical sectional view through end parts of the product container appearing in Fig. 5 and on a scale enlarged there,- over.

Fig. 7 is a transverse vertical detail sectional view through top and bottom portions of the container shown in Figs. 5 and 6 as taken on the line l-l of Fig. 6 and on a scale enlarged thereover.

Fig. 8 is a detail vertical sectional view as taken on the line 88 of Fig. 7 and on a scale enlarged thereover.

Fig. 9 is a perspective view of a certain product package, a plurality of which are adapted to be associated together .for use in the refrigerating operation.

Fig. 10 is a bottom view of the product package shown in Fig. 9 but on a somewhat smaller scale.

Fig. 11 is a view in side elevation of two of the product packages shown in Fig. 9, on the scale of Fig. 10. showing more particularly the manner in which such packages will stack vertically to provide an air circulating space betweenthem.

Fig. 12 is a detail vertical sectional view through top and bottom interengaging parts of the packages shown in Fig. 11, as taken on the line l2-l2 thereon, but on a considerably enlarged scale, better to show the interengagement of said parts.

Fig. 13 is a perspective view of a certain bar whereby the product packages of Fig. 9 are held in stacked relation, in the product container of Fig. 5.

Fig. 4 is a view in front elevation of an aircraft as in flight and carrying a pair of the pressure temperature chamber assemblies shown in Fig. 1.

Fig. 15 is a view in side elevation of the aircraft shown in Fig. 1, when carrying the improved pressure temperature assemblies.

Fig. 16 is a view in side elevation showing an arrangement in which a number of loaded product containers shown in Fig. 5 may be advantageously carried by a railroad car for distribu- 3 tion purposes, certain portions being broken away for illustrative purposes.

Fig. 17 is an end view of the parts shown in Fig. 16, certain portions being broken away for illustrativepurposes.

Fig. 18 is a view in side elevation showing one manner in which empty containers, such as shown in Fig. 5, may be stacked on a railroad car for return shipment.

Fig. 19 is an end view of the parts shown in Fig. 18.

, Fig. 20 is a schematic view in plan, with parts broken away, illustrating the refrigeratin means and power source.

The apparatus illustrated in the drawings for carrying out the improved method of refrigerating products, such for example as food products,

includes a pressure temperature chamber assembly, adapted to be quickly attached to and detached from an exterior part of a commercial aircraft, a product container adapted to be removably disposed in and carried by the pressure temperature chamber assembly and a pluralit of product packages, adapted to be stacked vertically in spaced apart relation in the product container during the refrigerating period.

Each pressure temperature chamber assembly, which has a smooth surfaced aerodynamic contour or shape, is made up of top and bottom halves or shells having a thin sheet metal covering of good heat conductivity. These shells are braced internally for strength and are so matched at their meeting margins as to be substantially sealed against atmospheric leakage. Each assembly also includes means whereby the pressure of the gaseous-like atmosphere, usually air, can be regulated in accordance with the temperature thereof, as well as means whereby said atmosphere may be recirculated between and about the product packages carried in the product container.

The product container is adapted to be disposed within the pressure temperature chamber assembly and to hold a pluralit of product carriers or packages in spaced relation. The body of the container, which is made of insulating material. is so correlated with respect to the pressure temperature chamber assembly as to be spaced from the ends and sides thereof. The ends of the container each includes a normally closed valve which, under a certain pressure condition, automatically opens to permit the gaseous-like atmosphere within the assembly to be circulated through the container in one direction from end to end and then into the other end of the assembly and back to the first mentioned end for recirculation.

The product packages or carriers are in the form of cubical containers made of good heat conducting material, such as thin sheet metal.

They are so formed, complementally at the top and bottom, as to stack in spaced relation without lateral relative shifting, the bottom of the product container being so formed as to receive and hold the bottommost packages or carriers against displacement. When the container is loaded with the stacked product pack-ages, locking means are applied to the topmost packages in a manner preventing shifting thereof in any direction.

The sealed pressure temperature chamber assembly Each pressure temperature chamber assembly, which is indicated as a. whole at 25, is in the form of a streamline hollow, thin-walled body, having a rounded or partly spherical leading end 26 and a somewhat pointed trailin end 21. The body of the assembly has its greatest diameter at substantially its mid portion and then gradually tapers toward said ends.

Preferably the assembly is made of top and bottom separable halves or shells 2B and 29 respectively of thin sheet metal having good heat conducting properties. Said shells have matched horizontal meeting margins or edges, each formed as an outwardly extending flange 28a-29a respectively, best appearing in Figs. 2 and 3. These flanges are detachably secured together in tight relation by removable strips 30 of U-shaped cross section, which substantially enclose said flanges.

The shell parts 28 and 29 are each provided with a plurality of longitudinally spaced archlike plates 3l-3la, 32-3211, 33-33a, 34 34a, 35-35a, 36-36a, 3'I-3'Ia, 38-38a, 39-3911 and 40-4011 respectively, beginning at the leading (left hand) end of the pressure temperature chamber assembly 25 and proceeding toward the trailing (right hand) end thereof as shown in Fig. 1. The plates 32, 33, 34, 3-5, 36, 31 and 38 of the shell 28 are operatively connected together by means of a weight distributing beam 4| arranged in the longitudinal median line of the shell and fastened to the respective plates by angle brackets 42-42.

Each of the plates from 3I-3la to 40-40:; inclusive, has an outer semicircular peripheral flange 43 that is engaged with and is fixed to the inner surface of the respective shell parts 28 and 29. The pairs of plates 31-32 and 3Ia-32a are each provided with a semicircular member 44-4411 and these members coact, when the shell parts 28-29 are engaged with each other, to form a tubular duct that opens at one end into a space 45 in the leading or front end of the assembly 25.

The plates 38-38:: are each provided in the meeting edges thereof with a semicircular flange 45-4511 and the flanges coact to provide an opening of the same size and coaxially with the duct provided by the members 44-4411 above mentioned.

The pairs of plates 33-33a, 34-3411, 35-35a, 35-360, and 31-31:: respectively are each provided with a second flange 46-460 and these flanges bound a rectangular recess 4| 4la respectively in each plate. Said recesses for the plates of each pair coact to define a rectangular opening 48 indicated only in Fig. 3. Each of the plates of the pairs just above mentioned is provided near its peripheral flange with openings 49, the purpose of which will appear later.

Spaced inwardly from each shell and extending between the pairs of plates 38-3811 and 39-39a is a semicircular wall 50 that coacts with the shell parts in forming an annular passage 5| as appears in Figs. 1 and 4. The front end of this annular passage registers with the openings 49 in the plates 38-3811 and the rear end of said passage registers with openings 52-52 in the plate parts 39-3911 so as to communicate with a space 53 as formed in the assembly 25 by the plate parts 39-3911 and 40-40a respectively. The plate parts 39-39:; are each so formed in their central portions as to coact in defining an opening 54 therein.

The plate part 39 functions as a support for a variable speed electric motor 55 that is located in a space 56 formed by the annular wall 50 and plate parts 38-3811 and 39-3911. This motor drives a turbo-compressor 51 disposed in a shroud 58 that communicates at its rear end with the opening 54 in the plate parts 88-89a and opens at its front end into the space 56. The purpose of said turbo compressor will appear later. x

The shell part 28 is provided witha pain of upright laterally spaced hollow stream lined fairing struts 59-58 and in each of which is located a pair of upright rods 66-66, by which the chamber assembly 25 as a whole may be pendently attached to a support above the same. For this reason each rod terminates at its top end in a rearwardly opening hook 6| as best shown in Fig. 1. The top end of each strut is outwardly flanged as at 58a for engagement with the support above mentioned.

62 indicates a pressure relief tube that opens at one end through the trailing end of the shell part 28 to atmosphere and opens at its other end into the space 53. This tube is provided with an electromagnetic valve 63 which is designed for remote control. The arrangement is such that the valve 63 may be remotely controlled by the operator in the pressurized cabin of the airplane. There are gages in the cabin which indicate the pressure and temperature within the assembly 25 as well as the pressure and temperature of the external atmosphere. Suitable electrical plug connections to the pressure and temperature responsive devices within the assembly 25 are provided (but not shown) whereby such devices may be electrically connected to the gages in the operators cabin.

It is pointed out that the shell part 28 is the weight supporting member of the chamber assembly 25 as a whole and-that the shell part 28 functions only as a bottom closure therefor when the before-mentioned food product container is arranged in position in said assembly. Therefore the bottom portion of the wall parts 32-38 of the shell part 28 is provided with openings 64 for the passage of certain bolts by which said product container is supported in place. These openings appear only in Fig. 2.

Food product container The food product container, which is indicated as a whole by the numeral 65, is best shown in Figs. 5, 6 and '7. It is in the form of a generally elongated rectangular box made of light weight, nonmetallic, heat insulating material such as laminated wood. It has a length approximating the distance between the pairs of plates 32-32a and 38-381: of the assembly 25 and has a generally square cross section so that it fits in the squared openings 48 of the pairs of plates 33-33a, 34-34a, 35-.35a, 36-3611 and 31-31a.

The product container includes an open top body comprising side walls 66-66, a bottom 61 and end walls 68 and 68 respectively. Preferably said walls are made up of plywood, so that each one of them is substantially hollow or has an air space therein as best appears in Figs. 6 and 7. The side and end walls are rabbeted about their top edges of receive a removable cover 16 with a good fit. On the inner surface of each side wall 66 near its top edge is a rail II. The mid part of each rail is offset from its associated side wall while its ends are secured directly to the associated wall.

The bottom wall 61 of the container is provided on its bottom side with longitudinal and transverse trusses 61a and 61b respectively to strengthen the same and the ends of said trusses are tapered as best shown in Figs. 1, 16, 17, 18 and 19 respectively. These trusses also function as skids for the respective container. Fixed to the top surface of the bottom wall is a plurality of longitudinally extending pairs of strips "-12 each having longitudinally spaced recesses 13 in the upper surface thereof. The strips I2 of each pair are spaced apart a distance greater than the distance between the strips of adjacent pairs oi. strips. These strips best appear in Fig. 7 and their function will soon appear.

The end walls 68 and 69 of the container 65 are each formed with a centrally arranged, outwardly extending tubular projection 15 and 16 respectively as best appears in Fig. 6 and each is surroundednear the associated end wall with an angle bar ring 11 whereby a good strong structure is afforded at this point. The horizontal flange of the ring 11 on the projection 15 is adapted to fit in the members 44-44a before mentioned and the like flange of the ring I! for the projection 16 is adapted. to fit in the opening as provided by the flange-parts 45-45a of the plates 38-3811. The vertical flange of each ring 11 is provided with threaded openings I8 (only one of which appears in Fig. 5) which are so disposed as to register with the openings 64-64 in the plate parts 32-38 before mentioned when the container 65 is disposed with in the assembly 25.

In the end wall 68 is a valve seat to accommodate a normally closed spring-pressed valve 8| that opens outwardly from said end wall when pressure conditions in the product container are such as to cause the same to open. The tubular projection 16 has an end wall 82 (see Fig. 6) in which is a valve seat 83 to accommodate a normally closed spring pressed valve 84 that opens inwardly of the extension 16 when the pressure conditions in the compartment 56 of the chamber assembly 25 are such as to cause the same to open. Thus both valves 8l-84 open in the same direction.

When the product container 65 is disposed in the chamber assembly 25, bolts 85 (see Fig. 2) are inserted through the openings 64 in the plates 32-38 to enter the openings 18 so as to hold the product container 65 in place in the chamber assembly 25. These bolts, of course, are applied before the shell part 29 is attached to the shell part 28 in the loading of a container 65 into the assembly 25. Conversely, in unloading the assembly 25, the bolts 85 are removed after the shell part 29 has been detached from the shell part 28.

Product package As before mentioned, the product container is adapted to receive and hold a plurality of produce packages and this in such a relation that the sides and top and bottom of each package are separated from the sides and top and bottom of adjacent packages so that the gaseous atmosphere or air in the product container 65 may pass between, about and all around the packages therein.

One of such packages, which is indicated as a whole at 86, best appears in Figs. 9 to 12 inclusive. This package is in the form of a cubical container made of thin sheet material of good heat conductivity. It maybe so-called tin can, if desired. Such a package comprises a body of thin sheet metal and includes four upright side walls 81-81, a bottom 88 and a top 89 having a centrally disposed flanged opening 89a therein (see Fig. 12). The side walls have a conventional seamed attachment with the top and bottom. A

78 circular lid 90 has a friction fit within the flanged opening 99a. The lid 90 is provided with a hole each bar spans the space between adjacent rows 99:: to permit passage of sufllcient air into or of packages in the top layer of packages so that out of the package to equalize the pressure witheach bar assists in holding down the packages in the package with that in the space surroundin said rows. when the bars no are in place and ing the package. After the product has been the cover In is applied to the container 65, the refrigerated or frozen this hole is sealed with bottom face of the cover exerts a hold down presparafllne or other suitable material. As the sure on all of the bars in the container 65 (see sides, top and bottom of the package are made Fig. 7).

of thin sheet metal, to stiflen the sides. I provide endwise and sidewise like inwardly depressed 10 Supporting earners for the chamber assembly 25 ribs 9i and to stiffen the bottom I provide the Primarily one or more of the loaded chamber diagonally disposed pressed ribs 92. assemblies 25 is intended to be carried pendently In each corner of the bottom, I provide a holfrom a support such as an exterior part of an low depressed boss 99 having upper and lower aircraft so that the said assemblies may be transparts 93a and 99b respectively of relatively large 16 ported to a high altitude where low temperature and small diameter that are connected by a air exists. In Figs. 14 and 15 I have shown a four flange or shoulder 94 disposed somewhat below motor'airplane that includesafuselage I90, laterthe plane of the bottom edge of the body as best ally extending wings llii-IM, operator's cabin appears in Fig. 12. The part 93b of smaller di- I02 and horizontal and vertical tail end rudders ameter has a rounded bottom 95 and is adapted go I03 and IM respectively. Each wing carries a to have applied thereto a non-metallic washer pair of nacelles I95 each including a motor or enor ring 96 to take the wear from the shoulder 94'. gine for driving a propeller I95.

In each corner of the top 99, coaxially with the In the present instance two of the pressure depressed bosses 93 in the bottom 99 before mentemperature chamber assemblies are shown tioned, in a hollow boss 91 that includes an up- 25 as carried by the aircraft. For the purpose of wardly and inwardly directed side wall 98 and balance one assembly 25 is disposed under each a downwardly extending cup 990 connected by a wing so as to extend in a fore and aft direction flange 99 to the wall 98, as appears in Fig. 12. and arranged in aplane between the two nacelles The upper end of the cup 98a is open so as to of the wing so as to depend from the underside receive the part 99b of the depressed boss 99 on thereof. Each wing includes internal parts for the bottom of another package or container. It engagement by the hooks 'ii of the rods 69 so is to be noted from Fig. 10 that the depressed that the associated assembly may be drawn bosses mentioned 91 forms a square and this snugly into position. In a smaller plane wheresquare has a width' approximating the spacing in only one assembly is to be carried thereby, said between the two strips 12 of a pair of strips on assembly maybe detachably connected to the botthe bottom of the container 65 and the spactom of the fuselage of said aircraft. ing between certain of the recesses 13 in said It will be observed from Fig. 14 that the asstrips. semblies 25-25 are spaced an equal distance With this arrangement of bosses, the packages from the longitudinal axis of the plane. Likemay be stacked vertically as indicated in Figs. wise, they are so disposed on the aircraft so as l and 11 and when so stacked there is an air to besubstantially at the center of pressure lines. space formed between the top and bottom of ad- In this way, the loaded assemblies do not inter- Jacent Pac ges in each vertical stack and befere with the stability characteristics of the plane. tween the sides of the packages in one stack and the sides of the packages in a laterally adjacent g 093mm)" stack. Assume that the packages 86 are properly filled W the container is stacked full f the with the products to be refrigerated and that the fil P ages 86. th tops f e P ges or lids 90 thereof have been applied thereto to close cans in the top layer thereof are disposed subt same, s m t filled packages are t stantially in the plane of e bottom edges of lo placedin the container 65 to make up the bottom the strips ll of the product carrier 65, and this layer. This is done by inserting the bosses 93 is somewhat below the plane of the bottom of on t tt of i packages i t t recesses the v r III as o v us fr m P e 7. The f r 13 of the strips 12 on the bottom of the product to hold e stacks of packages against shifting container 65. The successive layers of packages and dislodsm nt and thus maintain t a r spa so 86 are built up in the container, with the bosses arrangement before mentioned between said 93 of the packages above engaged in the recesses p s I pr v de a p u t of ld d wn ars. 91 of the ones below. Thus the packages in each one of which best appears in Fig. 1'3 bearing the horizontal layer are separated from the neighbors numeral I I0. It is preferably made of wood and in the same layer and each package in each vertihas a length approximating the inside width of so cal stack, while supported on the package below, the product container 65. It is wider than it is is separated therefrom by an air space, with the thick and has a gabled top and transverse openair spaces in communication with one another. ings III in the bottom. This bar is reinforced After the packages have been arranged as deon its bottom surface with a metallic strip 2. scribed, the hold down bars H0 are placed in po- End portions of this strip follow up the end of 98 sition as before described, after which the cover the bar and are then turned downwardly as III is applied to close the open top of the product hooks I I3 which are adapted for engagement with container 65. the bars ll of the container 65, as best appears The next step is to load the container into the in Fig. '7. pressure temperature chamber assembly -25. This The strip H2 for each bar is provided with deis accomplished while the shell member 29 is depressed bosses lll| I4 and these are spaced lontached from the shell member 28, which is now gitudinally and laterally of the bar so as to regopen at its bottom, it being assumed that the ister with rows of pockets 9'] in row of packages shell parts 28 0f bOth assemblies 25 are in place Ii in the top layer of such packages. On each upon the aircraft as before described. Each boss H4 is a wear taking washer ill. Thus, to loaded container 65 is now raised into its posithe products in said packages.

a closure for the latter, after which the strip sections 30 are applied. The aircraft with the loaded assemblies 25-25 attached thereto is ready to make its flight into the higher atmosphere to some predetermined destination.

The aircraft may now take off for flight to said destination and in said flight rises to a high altitude where low temperature air prevails. The operator in the cabin, from suitable instruments therein, which visually indicate the temperature of air in the assemblies 25-25, may now start the motor 55 in each assembly to drive the associated turbo compressor 51. This builds up a pressure in the compartment 55 of each assembly, sufficient to cause the valve 84 of the associated container 55 to open inwardly thereof and leave its seat 83 so that the air enters said container 55 and circulates through the various spaces between the packages 86. therein. The

pressure in each container 65 now builds'up to one which causes the valve 8| thereof to leave its seat 80 and move to open position so that the air passes through the duct as provided by the parts 4444a to enter the front or advancing end 45 of the associated assembly 25.

By reason of the rounded front end 45 of the assembly 25, the moving air in said front end is reversed in direction to follow the contour of the adjacent portions of the shell parts 2825 to pass successively through openings 4949 in the plate parts 3I-3Ia to 3838a inclusive and then into the front end of the annular passage 5| and out the rear end thereof into the space 53 between the pairs of plate parts 89-3911 and 48 40a respectively. The air then enters the turbo compressor for recirculation in the path mentioned. This path is indicated by the arrows appearing in Fig. 1.

In the passage or movement of the air through the container 65 and about and between the packages 85 therein, it absorbs heat units from As the air in its rearward movement contacts the internal surface of the cold metallic skin of the shell parts 28-29, said skin absorbs said heat units and dissipates them to the cold air surrounding each assembly 25 as a whole.

As before explained, the air within the assembly 25 is adapted to be circulated by means of the turbo-compressor 5|.- As the plane ascends above the earth's surface, the pressure, temperature and density of the atmospheric air decrease. Therefore, if the same number of pounds of air are to be circulatd within the assembly 25, (assuming the atmospherewithin the assembly to be substantially equalized with the external atmosphere) in order-to extract the same number of B. t. u.s per unit of time, a.

much greater number of cubic feet must be circulated. The characteristics of the turbo-compressor are such that a constant resistance pressure and weight of air may be delivered by increasing the speed and thus the volume. The motor 55, for driving the turbo-compressor, is of as the air density decreases, thereby maintaining the desired requirements.

The power for the variable speed motor 55,

for driving the turbo-compressor, is derived from a source in the fuselage I00 of the carrying aircraft and it is undercontrol of the pilot in the cabin I02. It is obvious that the final distribution of the frozen food products by aircraft may be impractical, due to short hauls from the concentration point, door to door delivery, etc. However, the product containers are so constructed that they may be moved as necessary by land or by water vehicles. Also, to maintain an adequate supply of such containers at the originating points of fresh products, they may, if desired, be shipped by highway or railway vehicles from the unloading point to the points of origin. This practice probably would be followed where no return load is available, as speed would not then be a factor and no processing of the product would take place.

Assume, therefore, that after the loaded product containers have been unloaded from the assemblies 25 of the carrying aircraft, it might be necessary to move such loaded containers to a point remote from an airplane landing field depot and reachable by a land vehicle such as a railroad car. As the containers 6565 are of such size that they cannot be convenientlyloaded in a conventional refrigerator car and as railroads at the present time do not have an adequate number of mechanically refrigerated cars capable of maintaining a temperature approximating zero F., a number of such loaded containers 65 (preferably four) may be placed upon a flat car I25 as appears in Figs. 16 and 1'7. Preferably such containers are disposed in side-byside pairs at the ends of the car so that the pairs of containers are spaced apart at the middle of the car, thus carrying four containers on a single flat car.

In order to provide the necessary refrigeration to maintain the already frozen product in proper condition, a small refrigerating unit is provided and so positioned as to refrigerate all four containers. Each two containers in longitudinal alignment on the car are connected by insulated ducts I21, the ends of which fit over and embrace the tubular extensions 15 and 16 respectively of the containers.

A flanged, heat insulated end or cover plate I28, having semicircular ends and fitting the end extensions 15-15, 'I5|6 at the respective ends of the car, are applied to container extensions so as to form a connecting duct therebetween, as apparent from Fig. 17. Thus the cover plates I28 and the ducts I2'I complete a recirculatory path through the four containers.

A mechanical refrigerating unit, operated by an internal combustion engine, not shown, is pro- "Wided. It is associated with the duct I21 so as to operate a blower I28 for moving air over the cooling coils of the refrigerating unit and for circucontainers 65-55 are loaded upon the car I25, the

the type that will automatically increase in speed refrigerating units I26 need only supply the heat .11. losses through the insulated sides, ends, top and bottom of the container. frigerating unit of the order used for refrigerating highway trucks will serve the purpose. By this system ordinary freight cars may be used and the necessity of building expensive refrigerator cars avoided.

The refrigeratingmeans and power source are illustrated schematically in Fig. 20. Therein I50 is an internal combustion engine, II a compressor, I52 the condensing coil and I53 the cooling coil in the path of the discharge from the blower I26. The engine I through pulleys I54 and I55 and connecting belt I56 drives the compressor I5I. The rotor of the blower I26 is driven from the engine I50 through shaft I51, pulley I58 thereon, pulley I59 on engine shaft and connecting belt I60.

In returning empty containers 65 to a point of reloading, they may be shipped by fiat car I25. In Figs. 18 and 19 I have shown one arrangement wherein nine of such empty containers are loaded on a flat car for shipment. They are arranged in two layers, with six containers in the first layer and three in the second one.

It is believed that the foregoing description will enable those skilled in the art, to which this invention relates, to appreciate ,the many advantages thereof. However, as by way of illustration and not by way of limitation, some of the outstanding advantages may be summarized as follows:

1. The invention makes possible the profitable carrying of cargo by commercial airways because the product can be processed en route.

2. Apparatus for the practice of the invention can be used in connection with existing type of aircraft.

3. Provides a great flexibility in the operation of airplanes. Those used for passengers can be converted to cargo ships or vice versa, or to mixed carriers quickly and easily.

4, Greatly reduces dehydration losses.

5. Provides methods and means whereby airplanes can be very quickly loaded or unloaded of their full cargo.

6. Reduces to a minimum the necessary handling of the product between producer and con sumer.

7. Provides for flexibility of interchange between airways, highways and railways.

8. Provides for high load ratio between product and carrying means.

9. Provides efficient means for the prevention of shifting of the cargo.

10. Provides packaging means especially adapted for use in refrigerating the product.

While, in describing the invention, I have referred in detail to the form, arrangement and construction of the parts involved, the same is to be considered only in the illustrative sense so that I do not wish to be limited thereto except as may be specifically set forth in the appended claims.

I claim as my invention:

1. In a refrigerating apparatus, the combination of a vehicle, a plurality of containers positioned on the vehicle in spaced relation, said con- Thus a portable re-.

tainers being formed to permit the passage of 12 therethrough, carried by said vehicle, conduit means extending between said containers and serving to connect the openings thereof, and means for refrigerating air and for circulating the refrigerated air through said conduit means and into said containers.

3. In a refrigerating apparatus, a vehicle, a plurality of containers arranged in spaced relation on the vehicle, and each formed for the passage of refrigerated air therethrough, conduit means connecting said containers, means for ref-rigerating said air, and means for circulating said refrigerated air through said containers and said conduit means.

4. In a refrigerating apparatus, a vehicle, a plurality of containers arranged in spaced relation on the vehicle, and each formed for the passage of refrigerated air therethrough, conduit means connecting said containers, means in a part of said conduit means for refrigerating said air, and means for circulating said air through said containers and said conduit means respectively.

5. In a refrigerating apparatus, a vehicle, a plurality of containers arranged in spaced relation on the vehicle and each formed for the passage of refrigerated air therethrough, conduit means connecting said containers, and means in a part of said conduit means for refrigerating and circulating said air through said containers and said conduit means.

6. In a refrigerating apparatus, a vehicle, a plurality of containers arranged in spaced relation on the vehicle, and each having an inlet and an outlet for the passage of refrigerated air therethrough, conduit means connecting the inlet of one container to the outlet of another container and coacting with said containers in forming a closed circulatory system for said refrigerated air, means for refrigerating said air, and means for circulating the refrigerated air through said system.

7. In a refrigerating apparatus, a vehicle, a plurality of containers arranged in spaced relation on the vehicle and each having an inlet and an outlet for the passage of refrigerated air therethrough, conduit means connecting the inlet of one container to the outlet of another container and coacting therewith in forming a closed circulatory system for said refrigerated air, and means in a part of said conduit means for refrigerating air and for circulating it through said system.

8. In a refrigerating apparatus, a vehicle, a container mounted thereon and having an inlet and an outlet for the passage of refrigerated air therethrough, unitary means for refrigerating and circulating said air and which means is adapted to be detachably connected to said inlet opening, and self-closing valve means positioned at said inlet and said outlet respectively, both of said self-closing valve means being movable to open position under the action of said medium when in circulation.

9. In a refrigerating apparatus, a vehicle, a plurality of containers mounted thereon, and each having an inlet and an outlet for the passage of refrigerated air therethrough, tubular projections associated with the inlet and the outlet of each container, conduit means detachably connected to the tubular projection associated with the inlet of one container to the tubular projection associated with the outlet of another container, means for refrigerating said air. and

13 means for circulating said air through said container and said conduits.

10. In combination, a vehicle, a plurality of heat insulated containers carried thereby and each having an inlet and an outlet for the possage therethrough of refrigerated air, conduit means detachably connecting the inlet of one container with the outlet of another container. and means in a part of said conduit means for refrigerating and circulating said air through said containers and said conduit means.

11. In combinaton, a vehicle, a plurality of heat insulated containers carried thereby and each having an inlet and an outlet for the passage therethrough of refrigerated air, conduit means adapted to detachably connect the inlet of one container with the outlet of another container, means in a part of said conduit means for refrigerating and circulating said air through said containers and said conduit means, and valve means positioned at the inlet and the outlet of each container, said valves being formed to open when said circulation is established through said containers and conduit means and being formed to close when said circulation is discontinued.

12. In combination, a vehicle, a plurality of side by side sets of heat insulated containers carried by and extending longitudinally of the tainer at each end of each set with the inlet of the container at each end of the other set to provide a closed circulating system therethrough, and means in a part of one of said conduit means for refrigerating and for circulating said air through the system as provided by the containers of both sets and the connecting conduit means.

13. In transport refrigerating apparatus, the combination of a vehicle, a product container removably mounted on the vehicle and having exterior insulated walls, said container having an endopening for the admission of a refrigerating air inwardly of the exterior insulated walls, a refrigerating unit carried by the vehicle and detachably connected to said container and positioned to supply a refrigerated air through said opening, and means for closing said opening when said refrigerating unit is removed from the container.

HARRY W. PRO'IZEILER.

REFERENCES. crran The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 480,718 Ennis Aug. 16, 1892 2,075,042 Knerr Mar. 30, 1937 2,162,213 Conn June 13, 1939 2,203,406 Dempsey,'Jr June 4, 1940 2,218,632 Baird Oct. 22, 1940 2,293,318 Stebbins Aug. 18. 1942 2,810,420 Graham "lab. 9, 1943 

